Question: Will there ever be a day where everything we have ever used or seen is sustainable?

Matthew Camilleri answered on 16 Nov 2014:

Well, my honest opinion is no. We were never really sustainable as a species and as time goes by we have become more destructive. It is highly possible that before we manage to be sustainable we would have destroyed so much of our own ecosystem that there will be nothing left for us to enjoy.

Apart from that, the actual definition of sustainability:
Sustainable development is the kind of development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
means that any resource we use would not be available for future generations, and thus it is not truly sustainable. This can be seen in wind farms, the elements needed for the magnets are rare, and there is a finite amount of them, and although these are better then oil for fuel generation, they are still not truly sustainable. The same can be said about solar panels.